A fourth ‘I’ of poverty ?

Current poverty measurement methodology does not allow a
definitive analysis of changes in distribution, through time or between countries,
which involve changes in the number or proportion of poor people. By reopening
some of the discussion which has taken place around the incidence,
intensity and inequality aspects of poverty, and by revisiting the continuity and
transfer axioms, we show that the Bourguignon and Fields poverty index allows
considerable ethical flexibility when its parameters are used to full advantage.
Significantly, a fourth dimension of poverty, the injustice of it, corresponding
closely with Rawls’s concern for the least advantaged, can also be admitted into
the picture once the poverty aversion parameter in the Bourguignon and Fields
index is fully understood and used appropriately. A novel application leads to a
perspective upon the entire class of relative poverty indices which has not been
seen before, and also generates both potentially interesting new poverty indices
and wider scope for cogent measurement.